The invention relates to apparatus for crushing hard materials, and more particularly to arrangements of this type in which the material to be crushed is introduced onto a disc.
In known arrangements of this type, the material is crushed by means of a plurality of heavy wheels which roll over the disc.
Such arrangements have several disadvantages. Firstly, it is difficult, if not impossible, to obtain uniformity in the grain size of the crushed material, or to adjust the apparatus to produce different desired nominal grain sizes or fractions.
Additionally, in spite of the relatively high cost and complexity of such known arrangements, the moving wheels are subject to rapid wear when the materials to be crushed are abrasive, such rapid wear being primarily a result of the different peripheral velocities of the disc and the contacting wheels.